feat: implement browser extension for media publishing and add backend support for media management

server/migrations/20260402153000_repair_plugin_installations_schema.down.sql

@@ -0,0 +1,4 @@
+-- No-op rollback.
+-- This migration repairs databases that already applied an older variant of
+-- 20260402140000 without plugin_installations. Dropping these objects on
+-- rollback would break databases created from the current baseline migration.